Semantic Authoring Markdown
XML was designed to be human readable, but not human writable. Graphical editors help, though they have their issues (like trying to find the right insertion point to add permitted elements). But graphical editors have a problem: when they hide the tags, they also hide the structure.
Semantic Authoring Markdown brings the ideas behind Markdown -- a natural syntax for writing HTML documents -- to structured writing. It creates a syntax that captures structure, like XML, but is easy to write in a text editor -- like markdown.